FAQs: Batteries


The battery comes in a cabinet that also contains the inverter, isolators and energy management computer (most other battery systems have additional boxes and enclosures). The cabinet measures 1650 high, 600 wide, 280mm deep and has a total weight of about 100kg.

The battery has a nominal capacity of 6.4 kWh with a standard charge rate of 3 kWh and a standard discharge rate for 3 kWh. During a power cut it can discharge at up to 3.6 kWh for short periods.


The battery has a lifespan of about 10 years. As part of the solarZero service we’ll replace the battery, as needed, once during the 20-year agreement, at no extra cost to you.


The battery will automatically power some key circuits in your home when there’s a power cut. Typically those circuits will include your kitchen and lounge so that you have lighting and can use low energy use appliances like your fridge, computers, router and TV. It will not support heavy load circuits like your oven, hot water cylinder or heat pump.

In the event of a power cut it will take a couple of seconds before devices connected to the circuits with battery backup come back on. These circuits will remain live until the battery reaches a preset minimum level of charge.

If it’s sunny, the solar panels will continue to power the backup circuits and charge the battery.

It is wise to switch off anything you don’t absolutely need to maximise the time remaining for the devices you do need.

If you try to draw too much power at once, the battery will shut down. If this happens you should switch off some devices and wait for the battery to switch back on.


We’ve programmed the battery to buy and use power at times that deliver the best rates for you.

It will charge up with grid power during the night when electricity rates are low. It will use this stored electricity to power your home at the start of the day. This will help minimise the amount of electricity you need to buy from the grid during the peak time in the morning when rates are high.

During the day the battery will charge up with surplus solar power. If required, it will top up with power from the the grid.That stored electricity will be used to power your home during the evening peak when grid rates are high again.


We’ve just completed the installation of the the solar system and storage battery. Before they can be switched on a new two-way meter will be installed and the set up needs to be checked by an independent inspector. We’ll arrange for both to be completed as soon as possible.

Usually the solar system and battery will be switched on by the inspector at the end of their visit if the meter change has been completed already. If that doesn’t happen we’ll call you and take you through the steps to switch them on yourself. Keep this guide handy.

Please do not switch the system on without talking to us first.

Steps for switching on the battery:

  1. The switch underneath the inverter (labelled: inverter), on the left hand side, should be turned to the “ON” position.
  2. The two DC isolators (labelled: PV DC isolator and Battery DC isolator) should be turned to the “ON” position
  3. The bypass switch on the bottom right of the inverter should be turned to the “Normal” position.

If, in the future, you think there may be an issue with the solar system, or battery, you can call us 24/7 on 0800 11 66 55.

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